1. Field of the Invention
The present invention relates to a manufacturing method for thin semiconductor device assemblies such as IC cards.
2. Description of the Related Art
An IC card, such as that shown in FIGS. 6A and 6B, has been hitherto known. In these drawings, a card substrate 1 is a rectangular element which is formed by either laminating, for example, a vinyl chloride resin, or is molded from a resin such as an ABS resin. A recess 2 is formed on either surface of the card substrate 1. An IC module 3 is fitted into the recess 2 of the card substrate 1, being fixed by a bonding agent. The IC module 3 is provided with a circuit substrate 5 that has a first surface on which a wiring circuit (not shown) is formed, and a second surface on which electrode terminals 4 are formed. The IC module 3 is also provided with an IC 7 mounted on the first surface of the circuit substrate 5. Plural electrodes (not shown) of the IC 7 are connected through wires 6 (not shown) to the wiring circuit of the circuit substrate 5. The wires 6, the IC 7 and so forth are sealed by resin 8. As shown in FIG. 6A, the electrode terminal 4 formed on the second surface of the circuit substrate 5 is exposed.
The thus-constructed IC card has been heretofore manufactured in the following manner. First, the IC 7 and other components are mounted on the first surface of the circuit substrate 5, and the resin-sealed IC module 3 is also formed. Next, the card substrate 1 having the recess 2 is formed. The IC module 3 is then fitted into the recess 2 and is fixed in place by a bonding agent.
Conventionally, the size of the external shape of the IC module 3 must therefore conform to that of the recess 2 of the card substrate 1. For instance, various industrial standards prescribe that the permissible tolerance in height between the electrode terminal on the IC card and the surface of the IC card around the electrode terminal be less than 0.1 mm. For this reason, it is necessary to employ a highly precise process for the external shape of the IC module 3 and the recess 2 of the card substrate 1. This increases manufacturing costs.
When an IC card is manufactured, a stage is required for fixing the IC module 3 into the recess 2 with a bonding agent. This step also increases the number of stages, thus making the manufacture of IC cards complicated.